This invention relates generally to integrated circuit read-only memories.
As is known in the art, read-only memory (ROM) and programmable read-only memory (PROM) components are widely used for storage of data such as program and microprogram control instructions because such components are relatively fast and non-volatile, retaining such instructions even when supply power is removed from the component. Further, such ROM/PROM components are typically fabricated as integrated circuit components. Each such ROM/PROM integrated circuit component generally includes a memory array of non-volatile memory elements coupled to addressing and output circuitry. In order to reduce the amount of power consumed by the addressing ciruitry when such ROM/PROM is not selected for reading the instructions stored therein, one type of ROM/PROM integrated circuit component is provided with a standby power enable circuit as described in U.S. Pat. No. 4,174,541, entitled "Bipolar Monolithic Integrated Circuit Memory With Standby Power Enable", inventor Charles R. Schmitz, issued Nov. 13, 1979, and assigned to the same assignee as the present invention. Thus, the user has the option of purchasing for a particular application either a non-power switched ROM/PROM component or a power switched ROM/PROM component.